Electric circuit breaker



June 22, 1937. .J. BIERMANNS ELECTRIC CIRCUIT BREAKER Filed NOV. 11, 1936 Inventor. Josef Biermanns,

His Attorney.

Patented June 22, 1937 UNI-TED STATES ATENT' OFFICE ELECTRIC CIRCUIT BREAKER Josef Biermanns, Berlin-Johamnisthal, Germany, assignor to General Electric (Company, a corporation of New York Application November Ill, 1936, Serial No. 110,398 lln Germany September 20, 1935 ll Claims.

of each other, have also been proposed and tend to produce generally the same result.

An essential factor in arc interruption is the primary cooling of the arc and subsequent penetration thereof by the comparatively cold exitinguishing agent to form a layer between the circuit breaker electrodes that is puncture-proof with respect to the circuit recovery voltage. The surface cooling enables the extinguishing agent to enter laterally into the arc and shift one of its base points or roots. This is effected in an improved manner in accordance with the present invention by spatial penetration of the arc body by means of two jets of arc-extinguishingfluid which are directed against each other so as to agitate and produce transverse as well as longitudinal fluid currents in the arc stream. These transverse currents formed at the point wherethe fluid jets impinge on one another, tend to 3 establish a dielectric layer for preventing reignition of the are after interruption at-a current zero.

In carrying out the invention a circuit breaker electrode or contact structure, and. preferably alsothe counter-electrode, are subjected to two jets of the arc-extinguishing agent, the two jets being directed towards one another in such a manner that they envelop the arc in hose-like of a hood. These hoods can function as screens or shields for preventing re-ignition of arcing by the heated arc gases.

My invention will be more fully set forth in the following description referring to the accom- 55 panying drawing, and the features of novelty a common axis and arranged in opposition to The jet guide members at the err-- which characterize my invention will be pointed out with particularity in the claims annexed to and forming a partof this specification.

The invention is illustrated diagrammatically and by way of example on the accompanying drawing on which Figure 1- is partly a side-view of, and partly an axial section through, one of the contacts and associated structure. Figure 2 is a plan view and shows the invention combined with a power separation switch, the portion at the left-hand end being shown in section. Figure 3 is a view in which two devices of the kind shown in Fig. 1 are'arranged oppositely to one another.

Referring to Fig. 1, there is provided relatively movable contact structure including a pinshaped electrode or contact 2 in an envelope l the gas issuing forth from said space 4 envelops the arc, in the proximity of its root or base, like a hose, whereby the arc root is fixed at the desired place and cooled intensely. The electrode shown in Fig. l with its envelope 1 that constitutes an electrostatic screen, 'as well as the counter-electrode (not shown in Fig. 1), which may be of the same design as the electrode shown or may have any other suitable shape, and be likewise arranged in an envelope of appropriate design, are

inthe open air.

The hood-like envelope i (Fig. 1) is flared away from the exhaust opening of the annular passage Q and is flattened on that side which is located opposite the counter-electrode (not shown, as

already stated) whereby a supporting or contacting surfacefor the counter electrode arranged substantially convex with respect thereto (when the device has been switched-on) is formed. The envelope l consists of metal and is preferably provided with a layer of some suitable insulating substance or composition,;especi2ly at the places locatedopposite the pin-shaped electrode 2. There is by this means prevented in a reliable manner fiash-over-of a high voltage arc between the electrode and envelope.

jumping over to the envelope consists in letting the head 5 of the electrode 2 which-may consist of an are resistant netaLfor instance tung- Another eontrivance to prevent the are from I suitably shaped counter-electrode 6. 8 is'now able to cause the automatic separation of the electrodes when the switch is tobe sten, project a little beyond the top face of the envelope I when the device is in switched-off state.

If two co-acting electrodes are used a particular effect will be attained whereby the jets of the gas under pressure which are directed towards one another and envelop the arc cylindrically bring about a strong whirling-through agitation of the arc with fresh air when they impinge upon one another.

The arrangement may be so designed that when the device is being switched-on the envelope and the electrode change their position relatively to one another, for which purpose either the envelope or the electrode is movable. Such an arrangement is shown, described and claimed in my copending application, Serial No. 109,561, filed November 6, 1936, for Electric circuit breaker.

In a practical constructional form of the invention as applied to a rotary separating or disconnecting switch the switching or are cham- 1 ber is formed by a pair of nozzle-like electrode structures associated with electrostatic screens serving as protective envelopes. As in the previous instance, an annular gap between the electrode and the envelope is formed through which a jet of gas under pressure is directed so as to envelop the arc in hose-like fashion. The are is cooled by the jet or jets when deflected in the manner above described. Flash-over of the arc to the protecting envelopes is effectively prevented by the guiding effect of the gas cylinder that envelops the are.

In the arrangement shown in Fig. 2 only one of the electrodes (2) is designed as a pin, whereas the counter-electrode 6 is of the segmental type and, if desired, may be extended in length so as to resemble a nozzle. With this arrangement the envelope I is shiftable upon the pinshaped electrode 2, for which purpose the envelope is connected with a sleeve 1 subjected to the action of a helical compression spring 8. The sleeve '1 is guided in a tubular guide member 9 attached to a supporting insulator I which also is used for the supply of the gas under pressure. The electrode 2 may be stationary, as shown in Fig.2, or may likewise be shiftable. The annular passage 4 (Fig. 1) through which the gas under pressure is supplied is located in Fig. 2 between the electrode 2 and the sleeve 1. The counter electrode is enclosed in a sleeve II aflixed to a double-arm I3 turnable on a pivot I2. The other arm of I3 is equipped with precisely such a set of members as are on the left-hand side.

When the switch is switchedeon, the envelope I I which is likewise flat at its free top-face contacts with the correspondingly shaped free top ,face of the envelope I (position of the parts shown in Fig. 2). When the envelope II is further moved, in the same direction, the envelope I will give way, counter to the pressure of the spring 8, and the electrode 2 will enter into the The spring switched-off.

The switch arrangement described can be designed and used also for multiple interruption. In the further constructional form shown in Fig. 3 the electrode 3| is again shaped as a pin and housed in a tubular guide member 32 in such a m anner that a tubular space 33 is formed through which the extinguishing agent is supplied. The member 32 may also in this case be combined with a tubular hood 34 which, especially if the electrodes are, or the arc respectively is, subjected to the blast or blasts of said agent in the open air, may consist of metal and may have an insulating covering for the prevention of flash-over of the arc and for homogenizing the electric field between the electrode and the counter-electrode 3I' (right-hand half of Fig. 3). The electrode 3I, or the hood 34 respectively, may be either stationary or movable in order to facilitate the closing and the separation of the contacts when switching takes place. The jet of the extinguishing agent passes in the direction indicated by the arrows (Fig. 3) within the tubular space 33, as well as outside of the same.

The counter-electrode 3I already mentioned in the preceding paragraph, as well as the hood 34' and the tubular piece 32, are designed precisely as the corresponding parts in the lefthand half of the figure and operate in the same manner. The arrows indicate again the direction in which the extinguishing agent is flowing.

The jets which this agent forms and which issue forth from the tubular members 32 and 32' are directed towards one another and impinge upon one another, envelop the arc body in a hoselike fashion and cool it intensely. When the jets impinge upon one another, they are deviated from their straight paths, penetrate into the core of the arc and whirl and agitate the are thereby.

It appears from the foregoing description that two equal jets of the extinguishing agent are used, these jets passing chiefly through the open air. The two jets may so impinge upon one another that they are directed accurately counter to one another which is best effected by arranging the two guide devices for the jets on a common'axis. It is, anyhow, also possible to arrange the guide devices at an angle with respect to one another so that the jets impinge upon one another prior to coming in contact with the arc. In this case the are also 'is acted on in the intended manner by being whirled and agitated, while at the same time the gas exhaust takes place in a preferred direction.-

The extinguishing agent may be any desired suitable gasiform or liquid fluid or mixtures thereof. It is particularly suited to the purpose in (view to employ compressed air or carbonic acid 7 or a similar substance, although if desired a mixture of air and steam can be used.

When making use of a gas under pressure the whirling action is due chiefly to the dynamic effect of the gas particles, but it is, finally, likewise possible to obtain the whirling action upon the arc body by an addition of chemically acting substances.

I claim:

1. In the electric circuit breaker art, the meth- 0d of interrupting an are formed between coacting electrodes which comprises directing simultaneously from each end of the are a jet of arcextinguishing fluid so as to, envelop a part of said are in hose-like fashion, said jets being independent of the arc pressure and in substantial alinement so as to impinge on each other.intermediate the ends of the arc.

2. .An. electric circuit breaker of the fluid blast type comprising relatively movable contacts separable to form an are upon opening of the circuit, and means independent of the arc pressure for directing two opposing jets of arc-extinguishing fluid generally longitudinally of said arc, each jet flowing from one of said contacts towards its coacting contact and having a 'substantiallyannular cross-section so as to envelop a part of said are in'hose-like fashion, said arc at the point of opposition of said jets being traversed and agi-- tated by said arc-extinguishing fluid.

3. An electric circuit breaker of the fluid blast type comprising-relatively movable contact structure separable along a substantially rectilinear path, and means independent of the arc pressure for directing opposing streams of arc-extinguishing fluid along said are path upon opening of the circuit, said streams being substantially annular in cross-section so as to envelop a part of the arc in hose-like fashion and impinging on each other so as both to traverse and exhaust radially of the arc. v

4. An electric circuit breaker of the fluid blast type comprising relatively movable contacts separable to form an are upon opening of the circuit, coaxial guide means coacting with each of said contacts for directing opposing jets of arcextinguishing fluid along the path of said are so as to impinge on each other intermediate the length of said are, said jets being independent ofv the arc pressure and substantially annular in cross-section so as to envelop a part of said arc in hose-like fashion.

5. An electric circuit breaker of the fluid blast I ing generally in alinement with the contact end of said contact pin during opening of the circuit.

6. An electric circuit breaker of the fluid blast type comprising relatively. movable contacts separable to form an are upon opening of the circuit, an insulating sleeve-like member coaxially arranged with respect to each of said contacts to 'form an annular fluid passage for guiding a jet of arc-extinguishing fluid'to said arc, said passages being substantially in alinement and continuous in the closed circuit position of said contacts so that said jets directly oppose each other in the path of the arc, and an annular flared member at the exhaust passage at each of said contacts for guiding radial exhaust therebetween of said arc-extinguishing fluid.

7. An electric circuit breaker comprising relatively movable contact structure including a pair of mutually convex members, the central axes of which are generally in alinement, said contact structure being in engagement at a point along said axes, and means for directing a fluid under pressure centrally of and between said convex members upon separation of said contact structure.

8. An electric circuit breaker comprising relatively movable contact structure including a pair of mutually substantially convex members, the central axes of which are generally in alinement, said contact structure being in engagement at a point along said'axes and separable to form an are located between said convex members upon opening of the circuit, and means for directing a fluid under pressure from one of said convex members centrally of and between said convex members upon separation of said contact structure so as to envelop a part of said are in hoselike fashion.

9. An electric circuit breaker comprising relatively movable contact structure including a pair of substantially convex members, the central axes of which are generally in alinement, said contact structure being normally in engagement at a point along said axes and separable to form an are located between said convex members, means for directing a jet of fluid under pressure from one of said convex members centrally of and towards the other of said convex members, and means for directing in opposition thereto a second jet of fluid under pressure from said other convex member centrally of and toward said first-named convex member, said fluid jets being substantially annular in cross-section so as to envelop a part of the arc in hose like fashion and exhausting radially between said convex members.

10. An electric circuit breaker comprising a pair of relatively movable contacts, a pair of electro-static shields associated with said contacts respectively, said shields having opposed mutually convex surfaces adjacent the point of separation of said contacts, and insulating means for directing a fluid under pressure through and centrally of at least one of said shields to said point of contact separation, said shields being adapted to separate in accordance with the circuit opening operation for directing exhaust of said fluid radially of said contacts between said convex surfaces.

11. An electric circuit breaker of the fluid blast type comprising a pair of relatively movable contacts, a pair of electrostatic shields associated with said contacts respectively, said shields having opposed mutually substantially convex surfaces adjacent the point of separation of said contacts, and means for directing a fluid under pressure through and centrally of at least one of said shields to said point of contact separation, said fluid directing means guiding said fluid along a path substantially annular in cross-section so as to envelop the arc at said point of separa-' tion, said shields being adapted to separate in accordance with the circuit-opening operation for directing exhaust of said fluid radially between said convex surfaces.

J OSEF' BIERMANNS. 

